src/charging-station/ui-server/UIHttpServer.ts

   1 import { IncomingMessage, RequestListener, Server, ServerResponse } from 'http';
   2
   3 import { StatusCodes } from 'http-status-codes';
   4
   5 import BaseError from '../../exception/BaseError';
   6 import type { UIServerConfiguration } from '../../types/ConfigurationData';
   7 import {
   8   ProcedureName,
   9   Protocol,
  10   ProtocolRequest,
  11   ProtocolResponse,
  12   ProtocolVersion,
  13   RequestPayload,
  14   ResponseStatus,
  15 } from '../../types/UIProtocol';
  16 import logger from '../../utils/Logger';
  17 import Utils from '../../utils/Utils';
  18 import { AbstractUIServer } from './AbstractUIServer';
  19 import UIServiceFactory from './ui-services/UIServiceFactory';
  20 import { UIServiceUtils } from './ui-services/UIServiceUtils';
  21
  22 const moduleName = 'UIHttpServer';
  23
  24 type responseHandler = { procedureName: ProcedureName; res: ServerResponse };
  25
  26 export default class UIHttpServer extends AbstractUIServer {
  27   private readonly responseHandlers: Map<string, responseHandler>;
  28
  29   public constructor(protected readonly uiServerConfiguration: UIServerConfiguration) {
  30     super(uiServerConfiguration);
  31     this.httpServer = new Server(this.requestListener.bind(this) as RequestListener);
  32     this.responseHandlers = new Map<string, responseHandler>();
  33   }
  34
  35   public start(): void {
  36     if (this.httpServer.listening === false) {
  37       this.httpServer.listen(this.uiServerConfiguration.options);
  38     }
  39   }
  40
  41   public stop(): void {
  42     this.chargingStations.clear();
  43   }
  44
  45   // eslint-disable-next-line @typescript-eslint/no-unused-vars
  46   public sendRequest(request: ProtocolRequest): void {
  47     // This is intentionally left blank
  48   }
  49
  50   public sendResponse(response: ProtocolResponse): void {
  51     const [uuid, payload] = response;
  52     if (this.responseHandlers.has(uuid) === true) {
  53       const { res } = this.responseHandlers.get(uuid);
  54       res.writeHead(this.responseStatusToStatusCode(payload.status), {
  55         'Content-Type': 'application/json',
  56       });
  57       res.write(JSON.stringify(payload));
  58       res.end();
  59       this.responseHandlers.delete(uuid);
  60     } else {
  61       logger.error(
  62         `${this.logPrefix(moduleName, 'sendResponse')} Response for unknown request id: ${uuid}`
  63       );
  64     }
  65   }
  66
  67   public logPrefix(modName?: string, methodName?: string, prefixSuffix?: string): string {
  68     const logMsgPrefix = prefixSuffix ? `UI HTTP Server ${prefixSuffix}` : 'UI HTTP Server';
  69     const logMsg =
  70       modName && methodName ? ` ${logMsgPrefix} | ${modName}.${methodName}:` : ` ${logMsgPrefix} |`;
  71     return Utils.logPrefix(logMsg);
  72   }
  73
  74   private requestListener(req: IncomingMessage, res: ServerResponse): void {
  75     if (this.authenticate(req) === false) {
  76       res.setHeader('Content-Type', 'text/plain');
  77       res.setHeader('WWW-Authenticate', 'Basic realm=users');
  78       res.writeHead(StatusCodes.UNAUTHORIZED);
  79       res.end(`${StatusCodes.UNAUTHORIZED} Unauthorized`);
  80       return;
  81     }
  82     // Expected request URL pathname: /ui/:version/:procedureName
  83     const [protocol, version, procedureName] = req.url?.split('/').slice(1) as [
  84       Protocol,
  85       ProtocolVersion,
  86       ProcedureName
  87     ];
  88     const uuid = Utils.generateUUID();
  89     this.responseHandlers.set(uuid, { procedureName, res });
  90     try {
  91       if (UIServiceUtils.isProtocolAndVersionSupported(protocol, version) === false) {
  92         throw new BaseError(`Unsupported UI protocol version: '/${protocol}/${version}'`);
  93       }
  94       req.on('error', (error) => {
  95         logger.error(
  96           `${this.logPrefix(moduleName, 'requestListener.req.onerror')} Error on HTTP request:`,
  97           error
  98         );
  99       });
 100       if (this.uiServices.has(version) === false) {
 101         this.uiServices.set(version, UIServiceFactory.getUIServiceImplementation(version, this));
 102       }
 103       if (req.method === 'POST') {
 104         const bodyBuffer = [];
 105         req
 106           .on('data', (chunk) => {
 107             bodyBuffer.push(chunk);
 108           })
 109           .on('end', () => {
 110             const body = JSON.parse(Buffer.concat(bodyBuffer).toString()) as RequestPayload;
 111             this.uiServices
 112               .get(version)
 113               .requestHandler(this.buildProtocolRequest(uuid, procedureName, body ?? {}))
 114               .catch(() => {
 115                 this.sendResponse(
 116                   this.buildProtocolResponse(uuid, { status: ResponseStatus.FAILURE })
 117                 );
 118               });
 119           });
 120       } else {
 121         throw new BaseError(`Unsupported HTTP method: '${req.method}'`);
 122       }
 123     } catch (error) {
 124       logger.error(
 125         `${this.logPrefix(moduleName, 'requestListener')} Handle HTTP request error:`,
 126         error
 127       );
 128       this.sendResponse(this.buildProtocolResponse(uuid, { status: ResponseStatus.FAILURE }));
 129     }
 130   }
 131
 132   private authenticate(req: IncomingMessage): boolean {
 133     if (this.isBasicAuthEnabled() === true) {
 134       if (this.isValidBasicAuth(req) === true) {
 135         return true;
 136       }
 137       return false;
 138     }
 139     return true;
 140   }
 141
 142   private responseStatusToStatusCode(status: ResponseStatus): StatusCodes {
 143     switch (status) {
 144       case ResponseStatus.SUCCESS:
 145         return StatusCodes.OK;
 146       case ResponseStatus.FAILURE:
 147         return StatusCodes.BAD_REQUEST;
 148       default:
 149         return StatusCodes.INTERNAL_SERVER_ERROR;
 150     }
 151   }
 152 }